The need for high resolution non-invasive imaging for mice and rats has seen an enormous increase in the last 10 years, particularly in the cardiovascular and cardiopulmonary field. The advent of transgenic animal models and the interest in assessing the peripheral vasculature, stem cell and gene therapy in vivo, and tumorigenic growth has led to a surge in multiple uses for this instrumentation. It is paramount for an academic institution to provide state-of-the-art ultrasound equipment that offers a wide range of temporal and spatial resolution sufficient for assessing cardiovascular function, blood flow, and peripheral circulation in the rodent model. This proposal requests funding for a state-of-the-art high resolution ultrasound bio microscopy device: the Visual Sonics Vevo 2100. The instrument will be managed and operated by the Research Resources Center at the University of Illinois at Chicago (UIC). The Center's mission is to allow a broad base of new and established investigators access to instrumentation that would ordinarily be cost-prohibitive. The benefits of this instrument to existing and newly recruited investigators are (1) the ability to perform blood flow quantification in muscle and tumors, and measure aortic and pulmonary artery regurgitation in hypertrophic and maladaptive hearts, (2) acquire data at higher frame rates and higher resolution while gating these data to electrophysiological events and (3) accurately measure muscle contractile abnormalities or changes in muscle contraction in a user-defined region of the myocardium. All investigators listed on this application have at least one currently funded R01. In addition, three investigators are part of a recently renewed Program Project Grant. Three of the major investigators also have multiple collaborative publications. Research projects requiring the use of this instrument can be broadly classified as: (1) maladaptive post-translational modifications and mutations linked to hypertrophic and dilated cardiomyopathies, (2) genetic and stem cell based approaches to rescue hearts from failure imposed by myocardial infarction, hypertension and mutations of sarcomeric proteins, (3) pulmonary vascular and right heart function, and (4) muscular dystrophy, and (5) oxidative stress associated with peripheral ischemia in skeletal muscle.